A related conventional vehicle body structure is described in Japanese Laid-Open Patent Application No. 2007-22485.
In the body structure described in Japanese Laid-Open Patent Application No. 2007-22485, as shown in FIG. 12, stepped load receiving members 104 are disposed on an upper surface of a cross member 102 constituting a vehicle cabin floor 102f and are secured to both side portions of the cross member 102 in a vehicle widthwise direction. Each of the load receiving members 104 is constructed to receive a load at an end surface 104f thereof. The end surface 104f is positioned opposite to a door box 103 of a rear door (not shown) in the vehicle widthwise direction. Therefore, when a collision load is applied to the vehicle rear door from a lateral side thereof, the collision load is transmitted to the end surface 104f of the load receiving member 104 via an impact beam 101 and the door box 103 of the rear door and is transmitted from the load receiving member 104 to the cross member 102. That is, the vehicle rear door can be supported by the load receiving member 104 and the cross member 102. Thus, the rear door can be prevented from protruding into a vehicle cabin.